There are still few new cards in the development. Some of them are rumored but one thing is for sure, Maxwell is not going to make its way to consumer market before 2014.
We have GTX 675, 685 and 695 coming in our way and at least one of them is going to be released before we hit 31st December 2012. Rest are believed to arrive in first quarter of 2013.
The reason for no Maxwell in 2013 is the architecture problem. It is going to be based on a 20nm fabrication process and from what I have read, Nvidia and AMD are facing problems from their end. The stability issues are greater than expected and that's why Maxwell series has gone back in development mode.
There is a lot of wait involved and since, new games are supposed to require more power and new levels of global illumination, smokes, depth, 3D, surround, etc., I think the wait will pay off.